Mouth-prop.



No. 801,841. PATENTED 0GT.17,1905. J.B.BESANT.

MOUTH PROP.

APPLICATION mum JAN. 5. 1905.

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TINITED STATES PATENT OFFICE.

JOSEPH B. BESANT, OF SARANAO LAKE, NEW YORK, ASSIGNOR OF ONE- HALF TOALFRED L. DONALDSON, OF SARANAC LAKE, NEW YORK.

MOUTH-PROP.

Specification of Letters Patent.

Patented Oct. 17, 1905.

Application filed January 5, 1905. Serial No. 239,705.

To all whom it may concern:

Be it known that I, JOSEPH B. BESANT, a citizen of the'United States,residing at Saranac Lake, county of Franklin, and State of New York,have invented certain new and useful Improvements in Mouth-Props, ofwhich the following is a full, clear, and exact specification.

My invention relates to mouth-props for the use of dentists, surgeons,&c., for the purposeof holding the jaws of a patient distended duringoperations upon the teeth, jaw,tongue,&c., and thereby relieving thepatient of the muscular strain which follows from the enforced holdingof the jaws in aset extended position for a long time.

An object of my invention is the means whereby I impart a yieldingquality to the instrument without sacrificing space which should be usedto add to the stiffness of the device. By placing the yielding meansentirely to one side of and out of the pathof the extensible member'Ihave provided an instrument wherein the spring or other yielding deviceemployed may be of any desired length without increasing the length ofthe instrument when closed, in which the increase in the length of theextensible shaft likewise increases the extensibility of the device, anda stiff and strong structure is produced.

Other details of improvement are set out in the accompanying drawings,illustrating one form in which my improved mouth-prop may beconstructed, and in which Figure 1 is a side elevation of the saiddevice; Fig. 2, a vertical section of the same; Fig. 3, a similarsection taken on the line a a of Fig. 2. Fig. 1 is a view similar toFig. 2, showing the extensible member partly extended,the removablecushions being omitted. Fig. 5 is a top view of a part of the bodyportion in which theextensible member slides. Fig. 6 is a top view ofthe body portion of the said de vice, showing the outer shell insection, taken on the line b 5 of Fig. 1; and Figs. 7 and 8 are detailviews illustrating the pawl and spring-plate.

Allof the parts are somewhat enlarged in size for the purpose of clearillustration.

My improved device is composed of a main body portion 1 and anextensible member 2, and the said parts terminate at their outer ends inpockets 3 and 4, which receive and hold the cushions 5. Said cushionsare designed to rest upon the teeth of the patient when the device is inuse, and] prefer to make them for that purpose of some yieldingmaterial, such as cork, which will give slightly when in use and willhold firmly on the teeth. The cushions are removable for the purpose ofreplacing them when necessary.

The main body portion 1 comprises a shell or outer casing 6 and an innerrecessed plug 7 which is secured to the casing in any suitable manner,so as to be removable therefromas, for instance, by screw 8.

The extensible member of my device is composed of a flanged head 9,which forms cushion-pocket 3, and of a shank 10, removably attachedthereto-as, for instance, by screw 1-1which is provided withratchet-teeth 13.

The shank 10 fits snugly in a longitudinal channel or passage-way 14,formed in plug 7, so as to slide therein. .A pin 15 passes through shank10 at its lower part, and the ends of said pin slide in vertical slots16, (shown in dotted lines in Fig. 6,) which are formed in the plug 7 onthe side walls of passage-way 14. The upper ends of said slots forma'stop to limit the extensibility of the device and prevent theextensible member being accidentally pulled out. Other forms of stopsmay be used, if desired.

A pawl 17 receives the thrust of the extensible member 2 through ratchet13 and communicates the same, through plate 18 and spiral spring 19, tothe cushion 5 on the end of body portion 1. The pawl is journaled on apivot-bearing 20, which is mounted in slots 21 in the side walls of theplug 7. These slots receive the pivot-bearing 20, which slides therein,and are long enough to permit the proper compression of spring 19.

It will be observed that the spring 19 is entirely to one side and outof the path of travel of the shaft 10, and by this arrangement Iamenabled to employ a spring of suitablelength without unduly increasingthe length of the prop, and thereby to increase the length of shaft 10,whereby the stability of the prop is increased.

Suitable means areprovided to hold the forward part of the pawl normallyagainst ratchet I sure upon key 23, which is removably attached to therear end of the pawl by screwing or in any other suitable way.

Pawl 17 is provided at its extreme rear end with a reduced portion 24:,which enters a narrow slot 25 in the plate 18, in which it plays as thekey 23 is depressed. The shoulders formed by the reduced portion 2 1bear upon the plate 18 and compress spring 19.

Spring 19 is confined in an annular pocket or cavity 26, formed in theplug 7 directly beneath' the pawl 17, and the plate 18 fits snugly inthis cavity, so as to slide therein. The wall of cavity 26 and the shell6 are slotted at 27 to permit the shank of key 23 to slide therein asthe spring 19 is compressed.

The casing should be slotted only sufliciently to permit the freemovement of said shank, so as to exclude liquids therefrom as much aspossible. A removable cover 28 is placed over the upper part of bodyportion 1, which is designed to prevent the entrance of liquid therein.This is cut out sufficiently to permit the free passage of shank 10.

My mouth-prop is designed to be taken apart for the purpose of cleaningthe same. This is accomplished as follows: Remove the cushions 5,unscrew screw 11, when head 9 may be removed, remove cover 28, key 23,and screw 8, and slip off the shell 6, carrying lower pocket 1. stop pin15 may then be pushed out and shank 1O removed. The pivotbearing 20 isthen pushed out of position, and the pawl 17, plate 18, and spiralspring 19 may be removed, when the device may be easily cleaned andreassembled.

In operation my device is inserted in the mouth so that the removablecushions rest .upon the teeth. The jaws are then opened to the properposition, and the extensible member is extended by pressure of thefingers upon the upper head until the device firmly holds the jawsdistended. Should it be desirable to relax the tension upon the jaws, apressure of the finger upon the key 23 will permit the device to bereduced in length, and when it is desired to remove the instrument thekey 23 is depressed until the device is brought together. In practice Iwill probably use the said device with a removable tip for use directlyupon the gums in cases where the teeth are missing, which is describedby me in an application for patent, Serial No. 230,7 30, filed October31, 1904.

It is evident that I have embodied in this application but one form inwhichmy invention may be embodied and that numerous changes andmodifications may be made without departing from my invention.

What I claim, and desire to secure by Let' ters Patent, is

1. A mouth-prop comprising an extensible member and a body portionrecessed to receive said extensible member, a rack on said extensiblemember and a pawl in said body portion, normally in contact with saidrack, means to release said pawl, yielding means between said pawl andthe base of said body portion contained within said body portion,substantially as described.

2. Amouth-propcomprisingabodyportion,

an extensible member sliding in said body portion, a ratchet on saidextensible member, a pawl in said body portion adapted to hold saidextensible member in its extended position, means for permitting alimited longitudinal movement of said pawl, and a spring incommunication with said pawl, providing a yielding connection betweensaid extensible member and said body portion, substantially asdescribed.

3. Ina mouth-prop, an extensible member, a rack thereon, a body member,recessed to receive said rack, a pawl therein in normal engagement withsaid rack to hold said extensible member in its extended position,sliding bearings for said pawl, yielding means intermediate said pawland the base of said body portion wholly outside the path of movement ofsaid rack, substantially as described.

1. In amouth-prop, an extensible member, a cushion at the end thereof, arack thereon, a body portion recessed to receive said rack, a cushion ontheend thereof, a pawl mounted in said body portion, sliding bearingstherefor, means for holding said pawl in engagement with said rack, andmeans for disengaging same, a spring lying wholly outside the path ofsaid rack and intermediate said pawl and body cushion and providingyielding means between said two cushions, substantially as described.

5. In a mouth-prop, an extension member, a

rack thereon, a body portion recessed to replate between said pawl andsaid spring, sub- I stantially as described.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

JOSEPH B. BESA'NT.

Witnesses:

EDWIN E. SUMNER, MARTIN H. HEIM.

